Originally Posted by
mactec54
Are that's another problem, when using (2) separate main AC power supplies like this, you will have a Ground loop, this is not a good idea to do this, as this too can cause the problems you are having also, which one is the worst, it hard to say as they are both quite bad, the Ground loop means you have no direct path to Earth /Ground so is not what you want.
The Estop shielded cable if it is grounded correctly then it will be ok, if it is not then it will create a problem
Twisted pairs, is very easy to do with two lengths of stranded wire cable, hold the two wires together in a vice or just clamp it to something, with it stretched out, put in your electric drill chuck and spin it until you have it twisted, then cut to whatever lengths you need